Key Engineering Materials Vol. 517

Abstract: This paper is concerned about the experimental study of twin round bamboo concrete infill composite parabolic tied arch. Experimental investigation is undertaken to validate the structural load bearing capacity of haritha infill arch. The infill arch is tested under three types of loading condition viz a) crown point loading, b) centre half loading and c) distributed point loading. The experimental results brings out the stiffness of the arch to be 1 kN/mm under crown point loading, 1.67 kN/mm under centre half loading and 1.17 kN/mm under distributed loading. The stresses in the materials are well within their allowable limits. Thus this paper is able to successfully report the structural strength of parabolic tied infill arch which promises to be a structural load bearing element. Since, there is no additional formwork required in casting of the arch, apart from the bamboo which itself acts like the formwork, lesser quantity of steel and very small thickness of concrete being involved, the arch qualifies to be a potential structural element for affordable housing and green constructions.

Abstract: The world crosses an energetic, environmental and social crisis without precedents. Architecture and Engineering are also responsible because the more used industrialized construction materials, as Portland cement, concrete and steel, in their production process, demand a lot of energy, cause serious impacts to the environment and need big investments. One possibility to decrease this problem is the non compulsory employment of products based on Portland cement and steel, but also using local materials with which is possible to construct worthily. This work has as proposal the development of a structural gypsum element reinforced with bamboo that can be used as lintel and against-lintel in the constructions. Prisms samples (4cm x 4cm x 16cm) of gypsum matrix reinforced with bamboo rods were prepared and flexural tests were made. To improve bond between the two materials, treatments in the bamboo were tested. The tests showed that the most efficient material for this treatment was epoxy glue. Pre-fabricated structural peaces in real size were also tested through flexion tests in laboratory and applied in an prototype built in the University campus. The casting was made using vibratory table. Results show that vibrated bamboo reinforced gypsum is viable to be used in small structural beams and even replacing wood peaces in roofs.

Abstract: Modern bamboo engineering material is a new fast-renewable green building material with light weight and high strength. Bamboo structure made of this material is a new structural system in China so far. A shake table test on a 1/3 scale model of a two-storey bamboo-frame pilot project were conducted, in which its dynamic responses including acceleration and relative interstory drift were tested. Finite element simulation was applied into structural analysis as well. The results indicate that this structure has satisfactory aseismatic property. Based on the results, some suggestions are put forward on aseismatic design and construction measures of bamboo frame structure.

Abstract: For the developed surface area of Xishuangbanna Dai's houses' roof be equal to about 85% of the total floor area, the reasonable choice for materials of roof frame has the important meaning for conserving energy and materials. Bamboo is a kind of fast-growing and renewable natural building material. Replacing the wooden roof frame with bamboo roof frame can achieve good ecological and economic effects. Bamboo pole has cavity, culm wall is thin and easy to split. These special characteristics of bamboo led to the existing structure technology of bamboo roof frame are very complex. In order to make up these defects, this paper proposed three methods for strengthening the bamboo poles. First, after the bamboo wall cut open, sticking the half log and fixing the log on the bamboo culm by pneumatically driven nail, makes bamboo pole can adopt the connection method of wood construction. Second, forms the partial solid body in the closed bamboo cavity, raises the bamboo pole's lateral bearing capacity. Third, does thicken processing for the bamboo wall in its specific positions, in order to enhance the anti-splitting ability. By using these structure measures, the joint structure of the new bamboo roof frame can be simplified, and the stability also greatly be proposed compared with the traditional bamboo roof frame.

Abstract: In this study, Moso bamboo (Phyllostachys pubescens) was used as the main raw material to design and manufacture a prefabricated modular bamboo house which could meet modern residential requirements. Bamboo was designed as building components after main physical-mechanical properties were tested and analyzed. After assembling bamboo together into construction components such as trusses and walls by using special connectors and clamps to combine and reinforce bamboo culms, strength of the prefabricated parts were tested. At last a modular bamboo house was built up. The results showed that use round bamboo for modern building is feasible.

Abstract: This paper presents an investigation on the mechanical properties of bamboos Mao Zhu (Phyllostachys Pubescens) strengthened with carbon fiber reinforced polymer (CFRP) and used as the substitute of steel substructures for a low carbon construction. At first, a series experimental study is carried out to investigate the compressive strength, bending strength and tensile strength of Mao Zhu, which is strengthened with CFRP by different ways. Then the mechanical properties of bamboos with different strengthening methods of CFRP are compared. The most efficient strengthening method is suggested for the carbon fiber strengthened bamboos, with such method the compressive strength and bending strength of Mao Zhu could be increased more than 30% and 44% compared with that of Mao Zhu without strengthening. Finally this paper discusses the advantages of the carbon fiber strengthened bamboos used as the substitutes of the steel substructures, for example the purlins and bracings of steel portal frame structures. The effective use of the bamboos as the substitutes of steel substructures will reduce the steel amount used in the steel portal frame structure, which is commonly used as low-rise factory building structure worldwide.

Abstract: Bamboos are smart natural tubes and a resistant material. Many species can be selected with 10 cm basal diameter, 12 m high and approximately straight longitudinal axis. A slender element like that has a relatively low load capacity under compression force. This limitation can be by passed through a composition of bamboo and cables. Through coherent design, this composition may produce an aesthetical and light mast with high axial compression resistance. This hybrid structure opens a big application for bamboo tubes, as for example, masts for the modern tents, known as tensile structures in the low weight architecture. Different compositions which use a large number of bamboos can be derived from this one. So, the mast mechanical performance investigation opens the way for another more complex systems understanding. In this paper, the design of a bamboo mast with 6 meters long is developed. A previous numerical investigation through SAP 2000 v14 structural analysis software was used for mast design and project. Cables and accessories; length and connections of the bracings and others constructive details are investigated until the conquest of a well fitted mast. A non destructive compression mechanical test of the mast rotation free at ends was done. Loads, tension in cables and lateral displacements were gauged in real time. Test results and numerical analysis show that masts can support compression forces many times bigger than bamboo itself.

Abstract: This paper is an exploratory study that aims to evaluate the prospects for the use of wood in residential construction in Brazil. For this purpose, a survey about the evolution of the stock of wooden houses was conducted. Social, environmental and economic indicators, which could interfere with the flow of Brazilian residential construction, were analyzed. The first results indicate that the stock of wooden houses has had a discrete growth (1.42%, from 1970 to 2009), but the percentage in the total number of houses has decreased (13.6%). Supply for housing demand has been provided by masonry. The population increase and the GDP demonstrated correlation with the building of houses and the changes in percentage between materials applied to it. Masonry is the construction technique preferred by the Brazilian. Most potential consumers (60.8%) declared that they could live in a wooden house. The aspects that would negatively influence the decision of living in a wooden house concerned market value, durability, fire and insect attack; and positively, was the material, construction process and patrimonial value. The image of a wooden house may be a greater problem than the material.

Abstract: The New Countryside Construction has been launched in China several years. In one hand, the amount of building construction in rural area in China is increasing rapidly. In some areas, vernacular buildings were abandoned because of their relatively poor performance of durability, seismic behavior, construction speed, and so on. But simply copying the conventional urban construction model is not a sustainable solution for diversified situations in rural area. On the other hand, in lots of the remote rural areas, the public facilities of villages are not convenient and perfect enough, because the transportation costs is much higher than construction costs. To solve these problems, the Wu Zhi Qiao (Bridge to China) Charitable Foundation organized a series of studies and construction practice in rural area of west China. Among them, gabion bridge and anti-seismic rammed earth house are two of the representative high-science and low-tech solutions for rural China. This paper will present how the local materials applied in rural areas in gabion bridge and anti-seismic rammed earth house projects, and discuss the performance and sustainability of these high-science and low-tech solutions.

Abstract: With the urbanization process, rural houses in Qin-Ling Mountain area changes spontaneous, some of these changes may lead to improvement of thermal performances, while others may be worse and results more energy consumption. Besides, in Qin-Ling Mountain area, energy consumption of rural houses for thermal comfort is mainly in winter. For these reasons, based on the field study in Qin-mao village in north Qin-Ling Mountain, the thermal environment in winter of new rural houses are tested and analyzed in this research. The result shows a close relation between indoor thermal performance and the outside wall materials, as well as location of rooms. And then the influence was quantified in 1-3. On this basis, defect of new rural house design is discussed, and advice is put forward to inprove its indoor thermal environment.